Electric-current transformer



(No Model.)

W. H. HORNBERGER. ELECTRIC CURRENT TRANSFORMER.

No. 510,640. Patented Dec. 12, 1893.

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UNITED STATES PATENT OEEIcE.

IVILLIAM H. IIORNBERGER, OF ELKHART, INDIANA.

ELECTRIC-CURRENT TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 510,640, dated December 12,1893.

Application filed March 31, 1893. Serial N0.468,540. (No model.)

To Cl/ZZ whom it may concern.-

Be it known that 1, WILLIAM H. HORNBER- GER, of Elkhart, in the county of Elkhart, in the State of Indiana, have invented new and useful Improvements in Current-'Iransformers; and I do hereby declare that the following is a full and accurate description of the same, reference being had to the accompanying drawings, wherein Figure 1 is a perspective view of a trans former built on my planthe case being omitted,and in operative position. Fig. 2 is a perspective view of the envelope detached. Fig. 8 is a perspective View of the core detached. Fig. 4 represents the key wedge.

Fig. 5 is a transverse section on the upper to be provided with an extra coil which may plane of the envelope. Figs. 6 and 7 represent modifications.

I The current transformer consists of two coils of insulated wire, in close contiguity, surrounded by a mass of magnetizable material. This envelope and the portion which extends within the coil or coils (known as the core) are commonly made from thin sheets of soft iron, these sheets being cut to proper size and shape. Sometimes the core has been made integral with the exterior part of the envelope, and sometimes both core and envelope are made from detachedpieces of thin iron packed around the coils, but always, so far as I know, the removal of the coils requires the case to be opened and the parts of the envelope separated. The case cannot be opened while in operative position and must therefore be taken down and usually sent to the manufacturer for repairs or at least removed to some shop where tools and skilled service can be procured.

The object of my invention is, to avoid these difficulties, first, by simplifying and cheapening the construction of the converter, and, second, to render it easy to remove the coils from the envelope and core without disintegrating said envelope, and Without opening the case or removing it from its operative place; and thus to make the renewal of one or both coils an easy matter, within the capacity of any person possessed of ordinary mechanical skill. To accomplish these objects, I make the envelope and core independent of the coils, complete wlthin themselves, their constituent parts being firmly burning out of the insulatlon does not afiect' the envelope, core or inclosing case. Hence, it is cheaper to repair than to purchase anew.

T0 guard against these accidents and delays,

by my invention it is not necessary to carry reserve converters in stock for temporary use.

My improvement renders it necessary only be substituted for the burned out coil in a few minutes time, without the removal of the converter case from its operative position, and the converter returned to duty.

As will be apparent, my invention is capable of a greatmany structural variations, and therefore I do not design to restrict myself to the particular forms shown and described. I employ the forms shown as illustrations only of practical forms. From the thin sheets of iron commonly employed for this purpose, I cut rectangular plates at, with central openings to receive the coils B, C. For convenience I will describe only the form which I have generally employed. At each side the central opening in plate a, is enlarged as at d. The several plates at, which go to make up the envelope E are packed and bound together in some convenient way. Sometimes I string on bolts f and by screw nuts or riveting press them solidly together, and sometimes I compress them by means of clamps of convenient construction, or other means exterior to the envelope. By these means the envelope becomes a structure capable of being handled as an entirety.

The core may be made separate and in one or more pieces. In Figs. 1, 2, 3, 5 it is shown in two parts G, G', similarly made up of laminae of the same thin sheet iron from which the envelope is constructed. The parts G, G, are similar, and each is made up of said laminae strung upon bolts h, which may be riveted or provided with screw nuts, to clamp the mass together. Each part G, G, of the core extends laterally beyond the coil, and is adapted to enter the notch d in the envelope, and when the two parts G, G, of the core are in place within the coils and the envelope E has been placed around the whole, the wedge keys I, I, are driven in, and thereby the parts are forced to make contact with the side or sides of the notches d, d, as shown. The notches d, may be of any convenient form other than rectangular, and the corresponding projecting ends of the core will be of simi ar shape- By these and similar means, the envelope and core parts are constructed so as to be handled as entireties, separate and separable-from the coils, and the several members may be disconnected and removable when released by the removal of the key wedges I so that the core and coils may be removed from the envelope and the core parts, and new coils inserted in a few minutes and the converter be again ready for duty. The laminae'of the envelope and core being equal in number and clamped together with the same force, will insure contact of each core lamina with the same envelope lamina; a point of considerable practical importance to the question of efliciency.

When it becomes necessary to remove the coil or coils from the converter, it is only necessary to open the bottom of the case by removing the switch and fuse box when the wedges I may be pulled downward and removed. The coils and core are then loose and free to be pulled downward out of the envelope and from the case. The new coils may be inserted in reverse order, the wedge keys being then inserted to hold the parts together. 4

Having described my invention, I claim- 1. In a transformer the combination with the coil, of an envelope consisting of a pile of lamina or plates lying parallel with the axis of the coil and forminga body inclosing and .of laminae or plates lying parallel with the axis of the coil and forming a body inclosing and continuous around the coil and having their edges presented thereto, a core consisting of laminae parallel with those of the envelope, situated within the coil and having portions projecting therefrom, and wedges or keys at the sides of the coil, extending transverse to the plates, engaging said projecting portions and'holding the edges of the laminae. of the core in intimate contact with the edges of the laminae of the envelope, substantially as set forth.

3. In a transformer the combination with the coil, of an envelope consisting of a pile of laminae or plates lying parallel with the axis of the coil'and forming'a body inclosing and continuous around the coil and having their edges presented thereto, a core consist ing of laminae parallel with those of the envelope, within the coil and separable therefrom and from the envelope, said core being made in two parts divided on a plane parallel with the axis of the coil and transverse to the laminae, and keys or wedges between said parts of the core and holding the edges of their laminae in intimate contact with the edges of the laminae of the envelope, substantially as set forth.

WM. H. HORNBERGER. In presence of E. D. 0. SMITH,

S, SMITH. 

